The present invention relates to a method for detecting an upcoming road situation for a vehicle. The invention also relates to a control unit configured to detect an upcoming road situation for a vehicle and a vehicle comprising such a control unit. The invention is applicable for vehicles, such as e.g. low-, medium- and heavy duty vehicles also commonly referred to as trucks. Although the invention will mainly be described in relation to a truck, it may also be applicable for other types of vehicles such as e.g. cars, etc.
Electrical driven vehicles are becoming increasingly popular since the demand on e.g, pollution etc. is continuously increasing from the market. An approach of electrical driven vehicles is to provide charging from charge segments positioned in e.g. the road where the vehicle is driven. These systems are often referred to as electrical road systems (ERS) and the vehicles are thus referred to as ERS-vehicles. These vehicles often comprise a conductor that is arranged to be positioned in contact with the charge segments of the road in order to receive charge current therefrom.
For safety reasons the charge segments are provided with electrical charge current only within a short time period before the ERS-vehicle arrives at the charge segment. The reason is that e.g. pedestrians or animals should not be able to touch a charge segment which is provided with electrical charge current. Accordingly, the charge segments are continuously switched on and off but the ERS-vehicle continuously receives charge current since the charge segments are turned on when the ERS-vehicle arrives at the respective segment. Hence, the charge segments are controllably supplied with electrical charge current for charging the vehicle. The electrical road system is thus able to detect the vehicle in order to decide when to turn on the electrical charge current.
Although the electrical charge segments receive information that an ERS-vehicle is located in the vicinity thereof, the interaction between the electrical charge segments and the vehicle is still in need of further improvements.
It is to provide a method that improves detection of an upcoming road situation in comparison to the prior art.
According to a first aspect of the present invention, there is provided a method for detecting an upcoming road situation for a vehicle, the vehicle comprising a control unit having a receiver configured to receive transmitted data from road system components along a road for the vehicle, wherein the method comprises the steps of receiving a signal from at least one electrical charge segment along the road, the signal being indicative of a present operational status of the at least one electrical charge segment; comparing the present operational status of the at least one electrical charge segment with a predetermined set of rules; and determining that the upcoming road situation at the at least one electrical charge segment ahead of the vehicle constitutes an increased safety risk for the vehicle if the present operational status of the at least one electrical charge segment ahead of the vehicle fails to fulfil at least one of the predetermined set of rules.
The wording “upcoming road situation” should be understood to mean that something has occurred ahead of the vehicle which may constitute a safety risk for the vehicle. For example, other vehicles ahead of the present vehicle are standing still due to e.g. a traffic accident, or that the road surface is icy, etc. These road situations may be associated with an increased safety risk if the vehicle operator, or the vehicle's active safety system, is unaware of the situation. The upcoming road situation is thus relating to the road ahead of the vehicle.
Furthermore, the wording “present operational status” of the at least one electrical charge segment should be understood to mean information that the electrical charge segment can receive from the vicinity thereof, such as the surrounding traffic situation at the electrical charge segment, etc. The wording also relates to property characteristics of the electrical charge segment, such as the temperature of the electrical charge segment, etc. Further detailed example embodiments of different present operational status of the electrical charge segments will be given below.
Still further, the wording “predetermined set of rules” should be understood to relate to rules which are specific for the specific and received present operational status of the electrical charge segments. Hence, there are different rules depending on the specific information received from the electrical charge segments. If, for example, a signal is received which indicates a specific surface temperature of the electrical charge segment, the predetermined rule may be a minimum temperature limit that may indicate that the road surface is icy and/or slippery. Detailed example embodiments of various predetermined set of rules are described further below.
Failure to fulfil at least one of the predetermined set of rules thus indicates that there is an increased safety risk for the vehicle at a position thereof.
The received signal indicative of the present operational status of the at least one electrical charge segment may be transmitted by wireless communication from each of the electrical charge segments along the road and received by e.g. the control unit of the vehicle. Any suitable technique known by the skilled person may be used for the wireless communication, such as e.g. Bluetooth, Wi-Fi, 3G/4G, laser signals, ultrasound signals, etc. Other alternatives are of course conceivable, the signal can, for example, be transmitted as a chain between consecutively arranged electrical charge segments of the road until it is received by the control unit of the vehicle. Furthermore, it should be understood that the invention is not limited to a situation where each of the electrical charge segments directly transmits a signal to the vehicle, the electrical charge segments may equally as well provide a signal, by wire or wireless, to a central control unit which analyses the signal and wirelessly transmits a signal to the vehicle with information relating to the present operational status of the electrical charge segments. Hence, the received signal may be received directly or indirectly from the electrical charge segments.
An advantage is that a hazardous traffic situation can be detected at an early point in time in comparison to e.g. standard forward-looking data collection systems, such as e.g. cameras, LIDAR, radar, etc. Hereby, the vehicle can be aware of the traffic situation at all positions of the road provided with the individually controlled electrical charge segments. A further advantage is thus that the vehicle, or the operator of the vehicle, is given proper information for planning the route ahead of the vehicle for being prepared for the upcoming situation, i.e. the operator will be given an increased awareness of the risk ahead of the vehicle. Hence, the invention provides for a dynamic update of the upcoming road situation which can be used in e.g. active safety systems of the vehicle, etc.
Furthermore, the present invention can be used in conjunction with existing active safety systems. In such a case, the present invention can be used as a compliment if, for example, camera vision, radar vision, laser vision, etc. is unable to track or identify a road situation constituting an increased safety risk for the vehicle. Also, the present invention may be utilized for verifying that existing road surveillance systems function properly. Hereby, the method may comprise the steps of receiving a signal from a road surveillance system of the road, the signal being indicative of an upcoming road situation, comparing the signal indicative of the upcoming road situation with the received signal of the operational status of at least one electrical charge segment positioned at the determined upcoming road situation, and determine that the signal indicative of the upcoming road situation is correct if the signal substantially corresponds to the received signal of the operational status of the at least one electrical charge segment.
According to an example embodiment, the received signal of the present operational status of the at least one electrical charge segment may comprise information relating to road specific events at the at least one electrical charge segment.
A road specific event should be understood to mean an event that takes place at the electrical charge segment. For example, traffic situation, icy road conditions, dynamic speed limits, road work, etc. may constitute various types of road specific events.
According to an example embodiment, the predetermined set of rules may comprise a road specific reference value determining a safety risk for the vehicle.
The road specific reference value may relate to the surrounding environment of the electrical charge segment or to conditions of the electrical charge segment. These reference values determine that there is an increased safety risk for the vehicle. For example, the road specific reference value may relate to vehicle speed for the vehicle(s) located at the electrical charge segments. The road specific reference value may be determined to constitute a safety risk for the vehicle if the speed of the vehicle(s) located at the electrical charge segment is below a predetermined threshold speed limit. The predetermined threshold speed limit may depend on e.g. the maximum allowable speed limit at the electrical charge segment, where the predetermined threshold speed limit is higher for a higher maximum allowable speed limit of the road. The road specific reference value may also relate to the surface temperature of the electrical charge segment, where it is determined to be a safety risk for the vehicle if the surface temperature of the electrical charge segment is below a predetermined threshold temperature limit. Other road specific reference values are of course conceivable and further examples will be given below.
According to an example embodiment, the method may comprise the steps of determining a distance from a current position of the vehicle to the position of the electrical charge segment determined to constitute an increased safety risk for the vehicle; and controlling the vehicle speed for the vehicle to be reduced at a predetermined distance before the vehicle arrives at the electrical charge segment.
Hereby, the vehicle operator does not need to take action of the vehicle which instead automatically reduces the speed of the vehicle well in time before it arrives at the position determined to constitute an increased safety risk.
According to an example embodiment, the method may comprise the step of providing a signal to a Human-Machine Interface (HMI) of the vehicle for warning a vehicle operator of the increased safety risk for the vehicle.
An advantage is that the operator can be given information of the traffic situation ahead of the vehicle. The operator may than, for example, determine to slow down before arriving at the position of the electrical charge segment constituting an increased safety risk, or decide to reroute the vehicle.
According to an example embodiment, the signal indicative of a present operational status of the at least one electrical charge segment may comprise an indication of a change of a structure property of the electrical charge segment.
Hereby, if it is determined that a structure property of the electrical charge segment has changed, this can be determined to be associated with a hazardous traffic situation. The change of a structure property is thus associated with a predetermined rule indicating when the change is determined to be associated with an increased safety risk.
According to an example embodiment, the change of a structure property of the electrical charge segment may comprise a change in electrical or mechanical properties of the electrical charge segment.
Changes in electrical properties, such as changes in capacitance, resistance, conductivity, impedance, etc. can indicate corrosion accumulation, snow deposits and other accumulated or instantaneous precipitation measurements that may constitute an increased safety risk for approaching vehicles. A change in electrical property may arise due to e.g. chemical spills, such as e.g. diesel, petrol or oil, on the electrical charge segment. Furthermore, a change in electrical properties may also be caused by severe amounts of water which can cause aquaplaning etc.
Changes in mechanical properties, such as vibration frequency shifts, mechanical stress, deformation of the electrical charge segments, etc. may imply that the ground surface beneath the electrical charge segment changes due to e.g. soil erosion rich may cause an uneven road surface or even a deformation of the road, such as a pothole, sink hole, etc.
Furthermore, a change in electrical or mechanical properties can be used to detect the presence of pedestrians or animals at the electrical charge segment. For example, a change in capacitance may indicate the presence of a pedestrian/animal on the electrical charge segment, or a change in vibration of the electrical charge segment may indicate the presence of a pedestrian/animal in the vicinity of the electrical charge segment.
According to an example embodiment, the signal indicative of a present operational status of the at least one electrical charge segment may comprise an indication of a surface temperature of the electrical charge segment.
Hereby, and as described above, if the surface temperature of the electrical charge segment is below a predetermined threshold limit, this may e.g. indicate that the road surface is icy and slippery.
According to an example embodiment, the signal indicative of a present operational status of the at least one electrical charge segment may comprise vehicle speed data for vehicles located at the at least one electrical charge segment.
Hereby, and as described above, if vehicles located at the electrical charge segment are driving below a predetermined threshold limit, this may imply that something has happened. Slow traffic, or stopped traffic, may by itself constitute a safety risk for the vehicle.
According to an example embodiment, the predetermined set of rules may comprise at least one of a minimum allowable vehicle speed level, maximum deceleration ratio level, or minimum distance to next coming vehicle on the road.
Hence, if the vehicles present at the electrical charge segments are traveling with too slow vehicle speed, decelerate too severely, or are driving to close to each other, this may constitute a safety risk or hazardous traffic situation for the approaching vehicle.
According to a second aspect of the present invention, there is provided a control unit configured to detect an upcoming road situation for a vehicle, the control unit comprising a receiver configured to receive transmitted data from road system components along a road for the vehicle, wherein the control unit is configured to receive a signal from at least one electrical charge segment along the road, the signal being indicative of a present operational status of the at least one electrical charge segment; compare the present operational status of the at least one electrical charge segment with a predetermined set of rules; and determine that the upcoming road situation at the at least one electrical charge segment ahead of the vehicle constitutes an increased safety risk for the vehicle if the present operational status of the at least one electrical charge segment ahead of the vehicle fails to fulfil at least one of the predetermined set of rules.
Effects and features of the second aspect are largely analogous to those described above in relation to the first aspect of the present invention.
According to a third aspect of the present invention, there is provided a computer program comprising program code means for performing any of the steps described above in relation to the first aspect when the computer program is run on a computer.
According to a fourth aspect of the present invention, there is provided a computer readable medium carrying a computer program comprising program means for performing any of the steps described above in relation to the first aspect when the program means is run on a computer.
According to a fifth aspect of the present invention, there is provided a vehicle comprising a control unit as described above in relation to the second aspect of the present invention.
It is thus to be understood that the vehicle should be able to receive data from electrical charge segments and/or a central control unit of an electrical road system. The vehicle may, for example, be an ERS-vehicle.
According to an example embodiment, the vehicle may further comprise a charging component adapted to receive electrical charge current from individually controlled electrical charge segments along a road, wherein the charging component is controlled by means of the control unit.
According to an example embodiment, the charging component may be adapted to conductively receive charge current from the individually controlled electrical charge segments along the road.
According to an example embodiment, the control unit may be configured to controllably direct the charging component towards the electrical charge segments along the road.
According to an example embodiment, the charging component may be positioned below the longitudinal frame of the vehicle, wherein the control unit is adapted to controllably direct the charging component towards electrical charge segments positioned in the ground surface of the road. Hereby, the vehicle receives electrical charge current from electrical charge segments positioned in the ground surface. It should however be understood that the electrical charge segments may be arranged on e.g. the safety fence of the road. In such situation, the charging component is preferably positioned on the side of the vehicle. Other alternatives are of course also conceivable.
Further effects and features of the fifth aspect are largely analogous to those described above in relation to the first aspect of the present invention.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.